The Numerical Simulation On The Trajectory Of Capsule Underwater-lauching And Capsule Separating Near The Free Surface

A two-dimensional hydroballistic numerical simulation method was established for such underwater launched missiles as those carried by non-powered capsule in the present paper. The method could calculate the whole underwater trajectory, including underwater trajectory of capsule and the separation trajectory of capsule and missile near the free surface.Some research proceedings of capsule separation technique, and of the mobile underwater-platform missile launching problems, were reviewed. Base on the sophisticated semi-theoretical and semi-empirical method, the rigid motion equations of missile and capsule were derived. In underwater launching condition, a comprehensive numerical model of the missile and capsule separation problem was established. The calculation methods were given for the adapter constraint forces and moments, the thrust force acted by gas generator for separation, and forces acted by wave interference.The trajectory numerical simulation program for non-powered capsule underwater launching and separation trajectory between capsule and missile near the free surface was developed. The trajectory numerical simulation program was verified by the results comparison between numerical simulation and the model test.Considering the above model deficiencies, the influence of the capsule base bubble was neglected, CFD method was used to simulate the bubble. A new parallel iteration algorithm for two different programs, Fluent and the trajectory numerical simulation program, was created by redevelopment of Fluent software and application of intermediate data files, therefore, the combination solution method was achieved for Fluent software and the code of trajectory numerical simulation. This method could simulate the trajectory of capsule more reasonable under the influence of base bubble.Finally, base on the above trajectory numerical simulation method, a number of calculations were given under varying parameters, such as height of separation, internal ballistic of gas generator, gap between adapters and capsule, etc. The rule of missile and capsule separation with respect to the variation of parameters was summarized. The results can be used to determinate the separation parameters.